MARRS: Mechanisms for Amplification of fusion Reaction Rates in Solids

The MARRS program aims to explore new theoretical predictions and new data suggesting high fusion reaction rates may be possible in relatively low-temperature solids (less than ~2,000 degrees Kelvin).

Decades of hype and mismeasurement have resulted in skepticism of the near-term potential for achieving fusion at low temperatures (e.g., the “cold fusion” fiasco in 1989).

However, since 2023, multiple, independent research groups have shared evidence – both theoretical and experimental data (references are in the BAA) – showing solid state fusion rates radically higher (~1018) than predicted by earlier models. Rates are still very low in absolute terms but point to an area of exploration where meaningful progress may be made. 

Concurrently, advances in measurement science now enable precise quantification of fusion rates, making it much easier to accurately assess experimental outcomes.

DARPA is funding MARRS as an opportunity to explore what amplification methods might be used to scale solid state fusion technology to useful rates for future applications of novel radiation sources in materials analysis and for power generation.

Why Fusion Matters

Nuclear fusion is the process of fusing two light atomic nuclei into a heavier nucleus, which releases a tremendous amount of energy. It is the process that powers the stars, including the sun. Fusion usually occurs at incredibly high temperatures (tens or even hundreds of millions of degrees Kelvin).

Many different projects to operationalize hot plasma fusion are under way around the world; it's getting closer to utility-scale viability, but costs and engineering risks remain for application of plasma fusion at utility-scale levels of power production. Work in MARRS on exploring fusion in solids is complementary to plasma fusion approaches.

If solid state fusion is successful, it is expected to enable small-scale (kilowatt- or megawatt-scale), small-footprint, distributed, mobile power generation; plasma fusion is anticipated to be better suited for large (gigawatt-scale), centralized power stations.

Exploring the Unknown

MARRS’ most important priority is to develop quantitative models based on clear understanding of fundamental mechanisms that underpin experimental results and to optimize conditions to achieve progressively higher fusion rates. 

The potential benefits of achieving solid state fusion are so high that knowing for sure if there is a “there” there or not is critical to national security.

If the program is successful in finding high fusion rates where the evidence suggests, the next goal will be to identify the most effective amplification mechanisms to determine how far it’s possible to scale those fusion rates.

Ideally, MARRS will outline a scalable path to power generation that can be explored more fully in future efforts.